<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>后盾人</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        body {
            height: 100vh;
            display: flex;
            flex-direction: column;
        }

        main {
            flex: 1;
            background: #f3f3f3;
        }

        footer {
            height: 50px;
            background: #eee;
            display: flex;
            flex-direction: row;
            justify-content: space-between;
            border-top: solid 1px #ccc;
        }

        footer section {
            flex: 1;
            /* background: red; */
            border-right: solid 1px #ccc;
            display: flex;
            flex-direction: column-reverse;
        }

        footer section:last-child {
            border-right: none;
        }

        footer section h4 {
            flex: 0 0 50px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            text-align: center;
            cursor: pointer;
        }

        footer section ul {
            display: flex;
            flex-direction: column;
            border: solid 1px #ccc;
            text-align: center;
            margin-bottom: 5px;
            margin: 5px;
            border-radius: 10px;
        }

        footer section ul li {
            flex: 1 0 50px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            border-bottom: solid 1px #ccc;
            cursor: pointer;

        }

        footer section ul li:last-child {
            border-bottom: none;
        }
    </style>
</head>

<body>
    <main></main>
    <footer>
        <section>
            <h4>教程</h4>
            <ul>
                <li>PHP</li>
                <li>CSS</li>
            </ul>
        </section>
        <section>
            <h4>教程</h4>
            <ul>
                <li>PHP</li>
                <li>CSS</li>
            </ul>
        </section>
        <section>
            <h4>直播</h4>
            <ul>
                <li>PHP</li>
                <li>CSS</li>
            </ul>
        </section>
        <section>
            <h4>软件</h4>
            <ul>
                <li>PHP</li>
                <li>CSS</li>
                <li>CSS</li>
                <li>CSS</li>
                <li>CSS</li>
            </ul>
        </section>
    </footer>
</body>

</html>